As a cap having an elastic turnover cover, there is known a cap which is integrally molded of a synthetic resin and having its cap body and cover hinged at three points, as is used in the container of Japanese Utility Model Laid-Open No. 34049/1988, for example. This cap is formed by integrally connecting a cap body and a cap opening cover into one piece by means of the three-point hinge. This three-point hinge structure is composed of: first two spaced hinges for connecting respective circumferential walls of the cap body and the cover placed thereon; an elastic band provided between the first two hinges; and second and third hinges for connecting each end of the elastic band to the cap body and the cover. The elastic band is formed into an L-shape such that it extends from the circumferential wall of the cap body to the top wall of the cover.
In order that the three-point hinged cap may be integrally molded of a synthetic resin, both the circumferential wall and the top wall of the cover are notched in accordance with the shape of the corresponding part of the elastic band for parting the mold. However, the notch on the top wall deteriorates the appearance of the cover. Even worse, the notch prevents the cover from completely sealing up the mouth of the cap body with the cover.
In order to eliminate the defects of the aforementioned example of the prior art, the present invention contemplates providing a cap structure having elastic bands which can be formed only at the respective circumferential walls of the cap body and the cover without notching the top wall of the cover, so that the cover may have an improved appearance and may seal up the mouth of the cap body in the closed position.